header{
    width: 100%;
    height: 2.04rem;
    position: relative;
    background-image: url(../images/去哪儿网_Qunar.com/mybgnew-20161111.jpg);
    background-size:cover;
    background-position: bottom;
    display: flex;
    justify-content: center;
    align-items: flex-end;
}
.b1{
    width: 0.65rem;
    height: 0.65rem;
    background-image: url(../images/去哪儿网_Qunar.com/avatar.png);
    background-size:cover;
    background-position: bottom;
    border: 0.03rem solid ghostwhite;
    border-radius: 50%;
}
header a{
    width: 0.6rem;
    height: 0.6rem;
    display: block;
    position: absolute;
    left: 0;
    top: 10%;
    text-align: center;
}
.b2{
    height: 1.1rem;
}
nav{
    /* height: 0.8rem; */
    /* margin-top: 0.2rem; */
}
.b3>p{
    height: 0.45rem;
    line-height: 0.45rem;
    
}
nav ul{
    height: 0.8rem;
    display: flex;
    justify-content: space-around;
    align-items: center;
    text-align: center;
    color: grey;
}
.b3{
    display: flex;
    border-bottom: 1px solid gainsboro;
}